1. Field of the Invention
The present invention relates to a portable electronic apparatus, and more particularly, to a portable electronic apparatus, such as a laptop personal computer, word processor, etc., having a keyboard at the front portion of a housing thereof.
2. Description of the Related Art
For example, a laptop personal computer generally comprises a housing and a keyboard at the front portion thereof. The housing is formed integrally with a keyboard frame, which presses the peripheral edge portion of the keyboard body, thereby retaining the keyboard in the housing. Keys of the keyboard are arranged at the front portion of the housing so as to project from an opening of the keyboard frame.
with this arrangement, the whole housing must be disassembled in replacing or inspecting the keyboard or in processing a printed board in the housing, thus requiring troublesome operation.
Accordingly, a novel arrangement has started to be used in place of the aforesaid one. In this modern arrangement, the top of the front portion of the housing is entirely opened so that a keyboard frame independent of the housing can be attached to the periphery of the front portion, and the keyboard is disposed inside the frame.
According to this improved arrangement, the printed board in the housing can be exposed by disengaging the keyboard and the keyboard frame from the front portion of the housing. If necessary, therefore, an extension memory, for example, can be easily additionally mounted in the housing without disassembling the whole housing. Further, the keyboard frame can be formed from a low-priced resin material which can be plated. If the keyboard frame is damaged or considerably worn, moreover, the keyboard frame alone can be replaced with a new one.
In the keyboard of the conventional portable electronic apparatus with the aforementioned arrangement, a large number of keys are mounted on the top of a rigid printed board having a circuit pattern, and a shielding plate is attached to the lower surface of the board. The shielding plate is used to prevent switching noises, attributable to key operation, from influencing the printed board in the housing, and its peripheral portion projects outward beyond the periphery of the printed board of the keyboard. The keyboard is attached to the front portion of the housing by superposing the projecting portion of the printed board on screw receiving bosses on the housing front and screwing them together from above. Also, screw receiving bosses integrally protrude downward from the inside of each frame portion of the keyboard frame, and the frame is attached to the housing front by means of screws threadedly passed through the bosses from under the housing.
The keyboard is inevitably large-sized, however, since the shielding plate has the projecting portion on its periphery, in order to allow the keyboard, including he printed board which cannot be provided with any screw receiving portion, to be attached to the housing. Since the screw receiving bosses are arranged on the inside of each frame portion of the keyboard frame, moreover, the individual frame portions have a great width, so that the keyboard frame is large-sized. In the conventional portable electronic apparatus, therefore, the keyboard including its surroundings is bulky, so that the whole housing is large-sized.